tools/bootconfig/main.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Boot config tool for initrd image
  */
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
 #include <endian.h>

 #include <linux/kernel.h>
 #include <linux/bootconfig.h>

 static int xbc_show_value(struct xbc_node *node, bool semicolon)
 {
 	const char *val, *eol;
 	char q;
 	int i = 0;

 	eol = semicolon ? ";\n" : "\n";
 	xbc_array_for_each_value(node, val) {
 		if (strchr(val, '"'))
 			q = '\'';
 		else
 			q = '"';
 		printf("%c%s%c%s", q, val, q, xbc_node_is_array(node) ? ", " : eol);
 		i++;
 	}
 	return i;
 }

 static void xbc_show_compact_tree(void)
 {
 	struct xbc_node *node, *cnode = NULL, *vnode;
 	int depth = 0, i;

 	node = xbc_root_node();
 	while (node && xbc_node_is_key(node)) {
 		for (i = 0; i < depth; i++)
 			printf("\t");
 		if (!cnode)
 			cnode = xbc_node_get_child(node);
 		while (cnode && xbc_node_is_key(cnode) && !cnode->next) {
 			vnode = xbc_node_get_child(cnode);
 			/*
 			 * If @cnode has value and subkeys, this
 			 * should show it as below.
 			 *
 			 * key(@node) {
 			 *      key(@cnode) = value;
 			 *      key(@cnode) {
 			 *          subkeys;
 			 *      }
 			 * }
 			 */
 			if (vnode && xbc_node_is_value(vnode) && vnode->next)
 				break;
 			printf("%s.", xbc_node_get_data(node));
 			node = cnode;
 			cnode = vnode;
 		}
 		if (cnode && xbc_node_is_key(cnode)) {
 			printf("%s {\n", xbc_node_get_data(node));
 			depth++;
 			node = cnode;
 			cnode = NULL;
 			continue;
 		} else if (cnode && xbc_node_is_value(cnode)) {
 			printf("%s = ", xbc_node_get_data(node));
 			xbc_show_value(cnode, true);
 			/*
 			 * If @node has value and subkeys, continue
 			 * looping on subkeys with same node.
 			 */
 			if (cnode->next) {
 				cnode = xbc_node_get_next(cnode);
 				continue;
 			}
 		} else {
 			printf("%s;\n", xbc_node_get_data(node));
 		}
 		cnode = NULL;

 		if (node->next) {
 			node = xbc_node_get_next(node);
 			continue;
 		}
 		while (!node->next) {
 			node = xbc_node_get_parent(node);
 			if (!node)
 				return;
 			if (!xbc_node_get_child(node)->next)
 				continue;
 			if (depth) {
 				depth--;
 				for (i = 0; i < depth; i++)
 					printf("\t");
 				printf("}\n");
 			}
 		}
 		node = xbc_node_get_next(node);
 	}
 }

 static void xbc_show_list(void)
 {
 	char key[XBC_KEYLEN_MAX];
 	struct xbc_node *leaf;
 	const char *val;
 	int ret;

 	xbc_for_each_key_value(leaf, val) {
 		ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX);
 		if (ret < 0) {
 			fprintf(stderr, "Failed to compose key %d\n", ret);
 			break;
 		}
 		printf("%s = ", key);
 		if (!val || val[0] == '\0') {
 			printf("\"\"\n");
 			continue;
 		}
 		xbc_show_value(xbc_node_get_child(leaf), false);
 	}
 }

 #define PAGE_SIZE	4096

 static int load_xbc_fd(int fd, char **buf, int size)
 {
 	int ret;

 	*buf = malloc(size + 1);
 	if (!*buf)
 		return -ENOMEM;

 	ret = read(fd, *buf, size);
 	if (ret < 0)
 		return -errno;
 	(*buf)[size] = '\0';

 	return ret;
 }

 /* Return the read size or -errno */
 static int load_xbc_file(const char *path, char **buf)
 {
 	struct stat stat;
 	int fd, ret;

 	fd = open(path, O_RDONLY);
 	if (fd < 0)
 		return -errno;
 	ret = fstat(fd, &stat);
 	if (ret < 0)
 		return -errno;

 	ret = load_xbc_fd(fd, buf, stat.st_size);

 	close(fd);

 	return ret;
 }

 static int pr_errno(const char *msg, int err)
 {
 	pr_err("%s: %d\n", msg, err);
 	return err;
 }

 static int load_xbc_from_initrd(int fd, char **buf)
 {
 	struct stat stat;
 	int ret;
 	u32 size = 0, csum = 0, rcsum;
 	char magic[BOOTCONFIG_MAGIC_LEN];
 	const char *msg;

 	ret = fstat(fd, &stat);
 	if (ret < 0)
 		return -errno;

 	if (stat.st_size < 8 + BOOTCONFIG_MAGIC_LEN)
 		return 0;

 	if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0)
 		return pr_errno("Failed to lseek for magic", -errno);

 	if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0)
 		return pr_errno("Failed to read", -errno);

 	/* Check the bootconfig magic bytes */
 	if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0)
 		return 0;

 	if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0)
 		return pr_errno("Failed to lseek for size", -errno);

 	if (read(fd, &size, sizeof(u32)) < 0)
 		return pr_errno("Failed to read size", -errno);
 	size = le32toh(size);

 	if (read(fd, &csum, sizeof(u32)) < 0)
 		return pr_errno("Failed to read checksum", -errno);
 	csum = le32toh(csum);

 	/* Wrong size error  */
 	if (stat.st_size < size + 8 + BOOTCONFIG_MAGIC_LEN) {
 		pr_err("bootconfig size is too big\n");
 		return -E2BIG;
 	}

 	if (lseek(fd, stat.st_size - (size + 8 + BOOTCONFIG_MAGIC_LEN),
 		  SEEK_SET) < 0)
 		return pr_errno("Failed to lseek", -errno);

 	ret = load_xbc_fd(fd, buf, size);
 	if (ret < 0)
 		return ret;

 	/* Wrong Checksum */
 	rcsum = xbc_calc_checksum(*buf, size);
 	if (csum != rcsum) {
 		pr_err("checksum error: %d != %d\n", csum, rcsum);
 		return -EINVAL;
 	}

 	ret = xbc_init(*buf, &msg, NULL);
 	/* Wrong data */
 	if (ret < 0) {
 		pr_err("parse error: %s.\n", msg);
 		return ret;
 	}

 	return size;
 }

 static void show_xbc_error(const char *data, const char *msg, int pos)
 {
 	int lin = 1, col, i;

 	if (pos < 0) {
 		pr_err("Error: %s.\n", msg);
 		return;
 	}

 	/* Note that pos starts from 0 but lin and col should start from 1. */
 	col = pos + 1;
 	for (i = 0; i < pos; i++) {
 		if (data[i] == '\n') {
 			lin++;
 			col = pos - i;
 		}
 	}
 	pr_err("Parse Error: %s at %d:%d\n", msg, lin, col);

 }

 static int init_xbc_with_error(char *buf, int len)
 {
 	char *copy = strdup(buf);
 	const char *msg;
 	int ret, pos;

 	if (!copy)
 		return -ENOMEM;

 	ret = xbc_init(buf, &msg, &pos);
 	if (ret < 0)
 		show_xbc_error(copy, msg, pos);
 	free(copy);

 	return ret;
 }

 static int show_xbc(const char *path, bool list)
 {
 	int ret, fd;
 	char *buf = NULL;
 	struct stat st;

 	ret = stat(path, &st);
 	if (ret < 0) {
 		ret = -errno;
 		pr_err("Failed to stat %s: %d\n", path, ret);
 		return ret;
 	}

 	fd = open(path, O_RDONLY);
 	if (fd < 0) {
 		ret = -errno;
 		pr_err("Failed to open initrd %s: %d\n", path, ret);
 		return ret;
 	}

 	ret = load_xbc_from_initrd(fd, &buf);
 	close(fd);
 	if (ret < 0) {
 		pr_err("Failed to load a boot config from initrd: %d\n", ret);
 		goto out;
 	}
 	/* Assume a bootconfig file if it is enough small */
 	if (ret == 0 && st.st_size <= XBC_DATA_MAX) {
 		ret = load_xbc_file(path, &buf);
 		if (ret < 0) {
 			pr_err("Failed to load a boot config: %d\n", ret);
 			goto out;
 		}
 		if (init_xbc_with_error(buf, ret) < 0)
 			goto out;
 	}
 	if (list)
 		xbc_show_list();
 	else
 		xbc_show_compact_tree();
 	ret = 0;
 out:
 	free(buf);

 	return ret;
 }

 static int delete_xbc(const char *path)
 {
 	struct stat stat;
 	int ret = 0, fd, size;
 	char *buf = NULL;

 	fd = open(path, O_RDWR);
 	if (fd < 0) {
 		ret = -errno;
 		pr_err("Failed to open initrd %s: %d\n", path, ret);
 		return ret;
 	}

 	size = load_xbc_from_initrd(fd, &buf);
 	if (size < 0) {
 		ret = size;
 		pr_err("Failed to load a boot config from initrd: %d\n", ret);
 	} else if (size > 0) {
 		ret = fstat(fd, &stat);
 		if (!ret)
 			ret = ftruncate(fd, stat.st_size
 					- size - 8 - BOOTCONFIG_MAGIC_LEN);
 		if (ret)
 			ret = -errno;
 	} /* Ignore if there is no boot config in initrd */

 	close(fd);
 	free(buf);

 	return ret;
 }

 static int apply_xbc(const char *path, const char *xbc_path)
 {
 	char *buf, *data, *p;
 	size_t total_size;
 	struct stat stat;
 	const char *msg;
 	u32 size, csum;
 	int pos, pad;
 	int ret, fd;

 	ret = load_xbc_file(xbc_path, &buf);
 	if (ret < 0) {
 		pr_err("Failed to load %s : %d\n", xbc_path, ret);
 		return ret;
 	}
 	size = strlen(buf) + 1;
 	csum = xbc_calc_checksum(buf, size);

 	/* Backup the bootconfig data */
 	data = calloc(size + BOOTCONFIG_ALIGN +
 		      sizeof(u32) + sizeof(u32) + BOOTCONFIG_MAGIC_LEN, 1);
 	if (!data)
 		return -ENOMEM;
 	memcpy(data, buf, size);

 	/* Check the data format */
 	ret = xbc_init(buf, &msg, &pos);
 	if (ret < 0) {
 		show_xbc_error(data, msg, pos);
 		free(data);
 		free(buf);

 		return ret;
 	}
 	printf("Apply %s to %s\n", xbc_path, path);
 	printf("\tNumber of nodes: %d\n", ret);
 	printf("\tSize: %u bytes\n", (unsigned int)size);
 	printf("\tChecksum: %d\n", (unsigned int)csum);

 	/* TODO: Check the options by schema */
 	xbc_destroy_all();
 	free(buf);

 	/* Remove old boot config if exists */
 	ret = delete_xbc(path);
 	if (ret < 0) {
 		pr_err("Failed to delete previous boot config: %d\n", ret);
 		free(data);
 		return ret;
 	}

 	/* Apply new one */
 	fd = open(path, O_RDWR | O_APPEND);
 	if (fd < 0) {
 		ret = -errno;
 		pr_err("Failed to open %s: %d\n", path, ret);
 		free(data);
 		return ret;
 	}
 	/* TODO: Ensure the @path is initramfs/initrd image */
 	if (fstat(fd, &stat) < 0) {
 		ret = -errno;
 		pr_err("Failed to get the size of %s\n", path);
 		goto out;
 	}

 	/* To align up the total size to BOOTCONFIG_ALIGN, get padding size */
 	total_size = stat.st_size + size + sizeof(u32) * 2 + BOOTCONFIG_MAGIC_LEN;
 	pad = ((total_size + BOOTCONFIG_ALIGN - 1) & (~BOOTCONFIG_ALIGN_MASK)) - total_size;
 	size += pad;

 	/* Add a footer */
 	p = data + size;
 	*(u32 *)p = htole32(size);
 	p += sizeof(u32);

 	*(u32 *)p = htole32(csum);
 	p += sizeof(u32);

 	memcpy(p, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
 	p += BOOTCONFIG_MAGIC_LEN;

 	total_size = p - data;

 	ret = write(fd, data, total_size);
 	if (ret < total_size) {
 		if (ret < 0)
 			ret = -errno;
 		pr_err("Failed to apply a boot config: %d\n", ret);
 		if (ret >= 0)
 			goto out_rollback;
 	} else
 		ret = 0;

 out:
 	close(fd);
 	free(data);

 	return ret;

 out_rollback:
 	/* Map the partial write to -ENOSPC */
 	if (ret >= 0)
 		ret = -ENOSPC;
 	if (ftruncate(fd, stat.st_size) < 0) {
 		ret = -errno;
 		pr_err("Failed to rollback the write error: %d\n", ret);
 		pr_err("The initrd %s may be corrupted. Recommend to rebuild.\n", path);
 	}
 	goto out;
 }

 static int usage(void)
 {
 	printf("Usage: bootconfig [OPTIONS] <INITRD>\n"
 		"Or     bootconfig <CONFIG>\n"
 		" Apply, delete or show boot config to initrd.\n"
 		" Options:\n"
 		"		-a <config>: Apply boot config to initrd\n"
 		"		-d : Delete boot config file from initrd\n"
 		"		-l : list boot config in initrd or file\n\n"
 		" If no option is given, show the bootconfig in the given file.\n");
 	return -1;
 }

 int main(int argc, char **argv)
 {
 	char *path = NULL;
 	char *apply = NULL;
 	bool delete = false, list = false;
 	int opt;

 	while ((opt = getopt(argc, argv, "hda:l")) != -1) {
 		switch (opt) {
 		case 'd':
 			delete = true;
 			break;
 		case 'a':
 			apply = optarg;
 			break;
 		case 'l':
 			list = true;
 			break;
 		case 'h':
 		default:
 			return usage();
 		}
 	}

 	if ((apply && delete) || (delete && list) || (apply && list)) {
 		pr_err("Error: You can give one of -a, -d or -l at once.\n");
 		return usage();
 	}

 	if (optind >= argc) {
 		pr_err("Error: No initrd is specified.\n");
 		return usage();
 	}

 	path = argv[optind];

 	if (apply)
 		return apply_xbc(path, apply);
 	else if (delete)
 		return delete_xbc(path);

 	return show_xbc(path, list);
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Boot config tool for initrd image
	*/
	#include <stdio.h>
	#include <stdlib.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <unistd.h>
	#include <string.h>
	#include <errno.h>
	#include <endian.h>

	#include <linux/kernel.h>
	#include <linux/bootconfig.h>

	static int xbc_show_value(struct xbc_node *node, bool semicolon)
	{
	const char val, eol;
	char q;
	int i = 0;

	eol = semicolon ? ";\n" : "\n";
	xbc_array_for_each_value(node, val) {
	if (strchr(val, '"'))
	q = '\'';
	else
	q = '"';
	printf("%c%s%c%s", q, val, q, xbc_node_is_array(node) ? ", " : eol);
	i++;
	}
	return i;
	}

	static void xbc_show_compact_tree(void)
	{
	struct xbc_node node, cnode = NULL, *vnode;
	int depth = 0, i;

	node = xbc_root_node();
	while (node && xbc_node_is_key(node)) {
	for (i = 0; i < depth; i++)
	printf("\t");
	if (!cnode)
	cnode = xbc_node_get_child(node);
	while (cnode && xbc_node_is_key(cnode) && !cnode->next) {
	vnode = xbc_node_get_child(cnode);
	/*
	* If @cnode has value and subkeys, this
	* should show it as below.
	*
	* key(@node) {
	* key(@cnode) = value;
	* key(@cnode) {
	* subkeys;
	* }
	* }
	*/
	if (vnode && xbc_node_is_value(vnode) && vnode->next)
	break;
	printf("%s.", xbc_node_get_data(node));
	node = cnode;
	cnode = vnode;
	}
	if (cnode && xbc_node_is_key(cnode)) {
	printf("%s {\n", xbc_node_get_data(node));
	depth++;
	node = cnode;
	cnode = NULL;
	continue;
	} else if (cnode && xbc_node_is_value(cnode)) {
	printf("%s = ", xbc_node_get_data(node));
	xbc_show_value(cnode, true);
	/*
	* If @node has value and subkeys, continue
	* looping on subkeys with same node.
	*/
	if (cnode->next) {
	cnode = xbc_node_get_next(cnode);
	continue;
	}
	} else {
	printf("%s;\n", xbc_node_get_data(node));
	}
	cnode = NULL;

	if (node->next) {
	node = xbc_node_get_next(node);
	continue;
	}
	while (!node->next) {
	node = xbc_node_get_parent(node);
	if (!node)
	return;
	if (!xbc_node_get_child(node)->next)
	continue;
	if (depth) {
	depth--;
	for (i = 0; i < depth; i++)
	printf("\t");
	printf("}\n");
	}
	}
	node = xbc_node_get_next(node);
	}
	}

	static void xbc_show_list(void)
	{
	char key[XBC_KEYLEN_MAX];
	struct xbc_node *leaf;
	const char *val;
	int ret;

	xbc_for_each_key_value(leaf, val) {
	ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX);
	if (ret < 0) {
	fprintf(stderr, "Failed to compose key %d\n", ret);
	break;
	}
	printf("%s = ", key);
	if (!val \|\| val[0] == '\0') {
	printf("\"\"\n");
	continue;
	}
	xbc_show_value(xbc_node_get_child(leaf), false);
	}
	}

	#define PAGE_SIZE 4096

	static int load_xbc_fd(int fd, char **buf, int size)
	{
	int ret;

	*buf = malloc(size + 1);
	if (!*buf)
	return -ENOMEM;

	ret = read(fd, *buf, size);
	if (ret < 0)
	return -errno;
	(*buf)[size] = '\0';

	return ret;
	}

	/* Return the read size or -errno */
	static int load_xbc_file(const char path, char *buf)
	{
	struct stat stat;
	int fd, ret;

	fd = open(path, O_RDONLY);
	if (fd < 0)
	return -errno;
	ret = fstat(fd, &stat);
	if (ret < 0)
	return -errno;

	ret = load_xbc_fd(fd, buf, stat.st_size);

	close(fd);

	return ret;
	}

	static int pr_errno(const char *msg, int err)
	{
	pr_err("%s: %d\n", msg, err);
	return err;
	}

	static int load_xbc_from_initrd(int fd, char **buf)
	{
	struct stat stat;
	int ret;
	u32 size = 0, csum = 0, rcsum;
	char magic[BOOTCONFIG_MAGIC_LEN];
	const char *msg;

	ret = fstat(fd, &stat);
	if (ret < 0)
	return -errno;

	if (stat.st_size < 8 + BOOTCONFIG_MAGIC_LEN)
	return 0;

	if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0)
	return pr_errno("Failed to lseek for magic", -errno);

	if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0)
	return pr_errno("Failed to read", -errno);

	/* Check the bootconfig magic bytes */
	if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0)
	return 0;

	if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0)
	return pr_errno("Failed to lseek for size", -errno);

	if (read(fd, &size, sizeof(u32)) < 0)
	return pr_errno("Failed to read size", -errno);
	size = le32toh(size);

	if (read(fd, &csum, sizeof(u32)) < 0)
	return pr_errno("Failed to read checksum", -errno);
	csum = le32toh(csum);

	/* Wrong size error */
	if (stat.st_size < size + 8 + BOOTCONFIG_MAGIC_LEN) {
	pr_err("bootconfig size is too big\n");
	return -E2BIG;
	}

	if (lseek(fd, stat.st_size - (size + 8 + BOOTCONFIG_MAGIC_LEN),
	SEEK_SET) < 0)
	return pr_errno("Failed to lseek", -errno);

	ret = load_xbc_fd(fd, buf, size);
	if (ret < 0)
	return ret;

	/* Wrong Checksum */
	rcsum = xbc_calc_checksum(*buf, size);
	if (csum != rcsum) {
	pr_err("checksum error: %d != %d\n", csum, rcsum);
	return -EINVAL;
	}

	ret = xbc_init(*buf, &msg, NULL);
	/* Wrong data */
	if (ret < 0) {
	pr_err("parse error: %s.\n", msg);
	return ret;
	}

	return size;
	}

	static void show_xbc_error(const char data, const char msg, int pos)
	{
	int lin = 1, col, i;

	if (pos < 0) {
	pr_err("Error: %s.\n", msg);
	return;
	}

	/* Note that pos starts from 0 but lin and col should start from 1. */
	col = pos + 1;
	for (i = 0; i < pos; i++) {
	if (data[i] == '\n') {
	lin++;
	col = pos - i;
	}
	}
	pr_err("Parse Error: %s at %d:%d\n", msg, lin, col);

	}

	static int init_xbc_with_error(char *buf, int len)
	{
	char *copy = strdup(buf);
	const char *msg;
	int ret, pos;

	if (!copy)
	return -ENOMEM;

	ret = xbc_init(buf, &msg, &pos);
	if (ret < 0)
	show_xbc_error(copy, msg, pos);
	free(copy);

	return ret;
	}

	static int show_xbc(const char *path, bool list)
	{
	int ret, fd;
	char *buf = NULL;
	struct stat st;

	ret = stat(path, &st);
	if (ret < 0) {
	ret = -errno;
	pr_err("Failed to stat %s: %d\n", path, ret);
	return ret;
	}

	fd = open(path, O_RDONLY);
	if (fd < 0) {
	ret = -errno;
	pr_err("Failed to open initrd %s: %d\n", path, ret);
	return ret;
	}

	ret = load_xbc_from_initrd(fd, &buf);
	close(fd);
	if (ret < 0) {
	pr_err("Failed to load a boot config from initrd: %d\n", ret);
	goto out;
	}
	/* Assume a bootconfig file if it is enough small */
	if (ret == 0 && st.st_size <= XBC_DATA_MAX) {
	ret = load_xbc_file(path, &buf);
	if (ret < 0) {
	pr_err("Failed to load a boot config: %d\n", ret);
	goto out;
	}
	if (init_xbc_with_error(buf, ret) < 0)
	goto out;
	}
	if (list)
	xbc_show_list();
	else
	xbc_show_compact_tree();
	ret = 0;
	out:
	free(buf);

	return ret;
	}

	static int delete_xbc(const char *path)
	{
	struct stat stat;
	int ret = 0, fd, size;
	char *buf = NULL;

	fd = open(path, O_RDWR);
	if (fd < 0) {
	ret = -errno;
	pr_err("Failed to open initrd %s: %d\n", path, ret);
	return ret;
	}

	size = load_xbc_from_initrd(fd, &buf);
	if (size < 0) {
	ret = size;
	pr_err("Failed to load a boot config from initrd: %d\n", ret);
	} else if (size > 0) {
	ret = fstat(fd, &stat);
	if (!ret)
	ret = ftruncate(fd, stat.st_size
	- size - 8 - BOOTCONFIG_MAGIC_LEN);
	if (ret)
	ret = -errno;
	} /* Ignore if there is no boot config in initrd */

	close(fd);
	free(buf);

	return ret;
	}

	static int apply_xbc(const char path, const char xbc_path)
	{
	char buf, data, *p;
	size_t total_size;
	struct stat stat;
	const char *msg;
	u32 size, csum;
	int pos, pad;
	int ret, fd;

	ret = load_xbc_file(xbc_path, &buf);
	if (ret < 0) {
	pr_err("Failed to load %s : %d\n", xbc_path, ret);
	return ret;
	}
	size = strlen(buf) + 1;
	csum = xbc_calc_checksum(buf, size);

	/* Backup the bootconfig data */
	data = calloc(size + BOOTCONFIG_ALIGN +
	sizeof(u32) + sizeof(u32) + BOOTCONFIG_MAGIC_LEN, 1);
	if (!data)
	return -ENOMEM;
	memcpy(data, buf, size);

	/* Check the data format */
	ret = xbc_init(buf, &msg, &pos);
	if (ret < 0) {
	show_xbc_error(data, msg, pos);
	free(data);
	free(buf);

	return ret;
	}
	printf("Apply %s to %s\n", xbc_path, path);
	printf("\tNumber of nodes: %d\n", ret);
	printf("\tSize: %u bytes\n", (unsigned int)size);
	printf("\tChecksum: %d\n", (unsigned int)csum);

	/* TODO: Check the options by schema */
	xbc_destroy_all();
	free(buf);

	/* Remove old boot config if exists */
	ret = delete_xbc(path);
	if (ret < 0) {
	pr_err("Failed to delete previous boot config: %d\n", ret);
	free(data);
	return ret;
	}

	/* Apply new one */
	fd = open(path, O_RDWR \| O_APPEND);
	if (fd < 0) {
	ret = -errno;
	pr_err("Failed to open %s: %d\n", path, ret);
	free(data);
	return ret;
	}
	/* TODO: Ensure the @path is initramfs/initrd image */
	if (fstat(fd, &stat) < 0) {
	ret = -errno;
	pr_err("Failed to get the size of %s\n", path);
	goto out;
	}

	/* To align up the total size to BOOTCONFIG_ALIGN, get padding size */
	total_size = stat.st_size + size + sizeof(u32) * 2 + BOOTCONFIG_MAGIC_LEN;
	pad = ((total_size + BOOTCONFIG_ALIGN - 1) & (~BOOTCONFIG_ALIGN_MASK)) - total_size;
	size += pad;

	/* Add a footer */
	p = data + size;
	(u32 )p = htole32(size);
	p += sizeof(u32);

	(u32 )p = htole32(csum);
	p += sizeof(u32);

	memcpy(p, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
	p += BOOTCONFIG_MAGIC_LEN;

	total_size = p - data;

	ret = write(fd, data, total_size);
	if (ret < total_size) {
	if (ret < 0)
	ret = -errno;
	pr_err("Failed to apply a boot config: %d\n", ret);
	if (ret >= 0)
	goto out_rollback;
	} else
	ret = 0;

	out:
	close(fd);
	free(data);

	return ret;

	out_rollback:
	/* Map the partial write to -ENOSPC */
	if (ret >= 0)
	ret = -ENOSPC;
	if (ftruncate(fd, stat.st_size) < 0) {
	ret = -errno;
	pr_err("Failed to rollback the write error: %d\n", ret);
	pr_err("The initrd %s may be corrupted. Recommend to rebuild.\n", path);
	}
	goto out;
	}

	static int usage(void)
	{
	printf("Usage: bootconfig [OPTIONS] <INITRD>\n"
	"Or bootconfig <CONFIG>\n"
	" Apply, delete or show boot config to initrd.\n"
	" Options:\n"
	" -a <config>: Apply boot config to initrd\n"
	" -d : Delete boot config file from initrd\n"
	" -l : list boot config in initrd or file\n\n"
	" If no option is given, show the bootconfig in the given file.\n");
	return -1;
	}

	int main(int argc, char **argv)
	{
	char *path = NULL;
	char *apply = NULL;
	bool delete = false, list = false;
	int opt;

	while ((opt = getopt(argc, argv, "hda:l")) != -1) {
	switch (opt) {
	case 'd':
	delete = true;
	break;
	case 'a':
	apply = optarg;
	break;
	case 'l':
	list = true;
	break;
	case 'h':
	default:
	return usage();
	}
	}

	if ((apply && delete) \|\| (delete && list) \|\| (apply && list)) {
	pr_err("Error: You can give one of -a, -d or -l at once.\n");
	return usage();
	}

	if (optind >= argc) {
	pr_err("Error: No initrd is specified.\n");
	return usage();
	}

	path = argv[optind];

	if (apply)
	return apply_xbc(path, apply);
	else if (delete)
	return delete_xbc(path);

	return show_xbc(path, list);
	}